/* CodeMirror main module
 *
 * Implements the CodeMirror constructor and prototype, which take care
 * of initializing the editor frame, and providing the outside interface.
 */

// The CodeMirrorConfig object is used to specify a default
// configuration. If you specify such an object before loading this
// file, the values you put into it will override the defaults given
// below. You can also assign to it after loading.
function createHTMLElement(el) {
	if ((document.createElementNS) && (document.documentElement.namespaceURI !== null)) {
		return document.createElementNS("http://www.w3.org/1999/xhtml", el)
	} else {
		return document.createElement(el)
	}
}

var CodeMirrorConfig = window.CodeMirrorConfig || {};

var CodeMirror = (function(){
  function setDefaults(object, defaults) {
	for (var option in defaults) {
	  if (!object.hasOwnProperty(option))
		object[option] = defaults[option];
	}
  }
  function forEach(array, action) {
	for (var i = 0; i < array.length; i++)
	  action(array[i]);
  }

  // These default options can be overridden by passing a set of
  // options to a specific CodeMirror constructor. See manual.html for
  // their meaning.
  setDefaults(CodeMirrorConfig, {
	stylesheet: "",
	path: "",
	parserfile: [],
	basefiles: ["util.js", "stringstream.js", "select.js", "undo.js", "editor.js", "tokenize.js"],
	linesPerPass: 30,
	passDelay: 200,
	continuousScanning: false,
	saveFunction: null,
	onChange: null,
	undoDepth: 50,
	undoDelay: 800,
	disableSpellcheck: true,
	textWrapping: true,
	readOnly: false,
	width: "100%",
	height: "300px",
	autoMatchParens: false,
	parserConfig: null,
	tabMode: "indent", // or "spaces", "default", "shift"
	activeTokens: null,
	cursorActivity: null,
	lineNumbers: false,
	indentUnit: 2
  });

  function wrapLineNumberDiv(place) {
	return function(node) {
	  var container = createHTMLElement("div"),
		  nums = createHTMLElement("div"),
		  scroller = createHTMLElement("div");
	  container.style.position = "relative";
	  nums.style.position = "absolute";
	  nums.style.height = "100%";
	  if (nums.style.setExpression)
		nums.style.setExpression("height", "this.previousSibling.offsetHeight + 'px'");
	  nums.style.top = "0px";
	  nums.style.overflow = "hidden";
	  place(container);
	  container.appendChild(node);
	  container.appendChild(nums);
	  scroller.className = "CodeMirror-line-numbers";
	  nums.appendChild(scroller);
	}
  }

  function applyLineNumbers(frame) {
	var win = frame.contentWindow, doc = win.document,
		nums = frame.nextSibling, scroller = nums.firstChild;

	var nextNum = 1, barWidth = null;
	function sizeBar() {
	  if (nums.offsetWidth != barWidth) {
		barWidth = nums.offsetWidth;
		nums.style.left = "-" + (frame.parentNode.style.marginLeft = barWidth + "px");
	  }
	}
	function update() {
	  var diff = 20 + Math.max(doc.body.offsetHeight, frame.offsetHeight) - scroller.offsetHeight;
	  for (var n = Math.ceil(diff / 10); n > 0; n--) {
		scroller.appendChild(document.createTextNode(nextNum++));
		scroller.appendChild(createHTMLElement("br"));
	  }
	  nums.scrollTop = doc.body.scrollTop || doc.documentElement.scrollTop || 0;
	}
	sizeBar();
	update();
	win.addEventHandler(win, "scroll", update);
	setInterval(sizeBar, 500);
  }

  function CodeMirror(place, options) {
	// Backward compatibility for deprecated options.
	if (options.dumbTabs) options.tabMode = "spaces";
	else if (options.normalTab) options.tabMode = "default";

	// Use passed options, if any, to override defaults.
	this.options = options = options || {};
	setDefaults(options, CodeMirrorConfig);

	var frame = this.frame = createHTMLElement("iframe");
	frame.frameBorder = 0;
	frame.src = "javascript:false;";
	frame.style.border = "0";
	frame.style.width = options.width;
	frame.style.height = options.height;
	// display: block occasionally suppresses some Firefox bugs, so we
	// always add it, redundant as it sounds.
	frame.style.display = "block";

	if (place.appendChild) {
	  var node = place;
	  place = function(n){node.appendChild(n);};
	}
	if (options.lineNumbers) place = wrapLineNumberDiv(place);
	place(frame);

	// Link back to this object, so that the editor can fetch options
	// and add a reference to itself.
	frame.CodeMirror = this;
	this.win = frame.contentWindow;

	if (typeof options.parserfile == "string")
	  options.parserfile = [options.parserfile];
	if (typeof options.stylesheet == "string")
	  options.stylesheet = [options.stylesheet];

	var html = ["<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.0 Transitional//EN\" \"http://www.w3.org/TR/html4/loose.dtd\"><html><head>"];
	forEach(options.stylesheet, function(file) {
	  html.push("<link rel=\"stylesheet\" type=\"text/css\" href=\"" + file + "\"/>");
	});
	forEach(options.basefiles.concat(options.parserfile), function(file) {
	  html.push("<script type=\"text/javascript\" src=\"" + options.path + file + "\"></script>");
	});
	html.push("</head><body class=\"editbox\" spellcheck=\"" +
			  (options.disableSpellcheck ? "false" : "true") + "\"></body></html>");

	var doc = this.win.document;
	doc.open();
	doc.write(html.join(""));
	doc.close();
  }

  CodeMirror.prototype = {
	init: function() {
	  if (this.options.initCallback) this.options.initCallback(this);
	  if (this.options.lineNumbers) applyLineNumbers(this.frame);
	},

	getCode: function() {return this.editor.getCode();},
	setCode: function(code) {this.editor.importCode(code);},
	selection: function() {return this.editor.selectedText();},
	reindent: function() {this.editor.reindent();},

	focus: function() {
	  this.win.focus();
	  if (this.editor.selectionSnapshot) // IE hack
		this.win.select.selectCoords(this.win, this.editor.selectionSnapshot);
	},
	replaceSelection: function(text) {
	  this.focus();
	  this.editor.replaceSelection(text);
	  return true;
	},
	replaceChars: function(text, start, end) {
	  this.editor.replaceChars(text, start, end);
	},
	getSearchCursor: function(string, fromCursor) {
	  return this.editor.getSearchCursor(string, fromCursor);
	},

	undo: function() {this.editor.history.undo();},
	redo: function() {this.editor.history.redo();},
	historySize: function() {return this.editor.history.historySize();},

	grabKeys: function(callback, filter) {this.editor.grabKeys(callback, filter);},
	ungrabKeys: function() {this.editor.ungrabKeys();},

	cursorPosition: function(start) {
	  if (this.win.select.ie_selection) this.focus();
	  return this.editor.cursorPosition(start);
	},
	firstLine: function() {return this.editor.firstLine();},
	lastLine: function() {return this.editor.lastLine();},
	nextLine: function(line) {return this.editor.nextLine(line);},
	prevLine: function(line) {return this.editor.prevLine(line);},
	lineContent: function(line) {return this.editor.lineContent(line);},
	setLineContent: function(line, content) {this.editor.setLineContent(line, content);},
	insertIntoLine: function(line, position, content) {this.editor.insertIntoLine(line, position, content);},
	selectLines: function(startLine, startOffset, endLine, endOffset) {
	  this.win.focus();
	  this.editor.selectLines(startLine, startOffset, endLine, endOffset);
	},
	nthLine: function(n) {
	  var line = this.firstLine();
	  for (; n > 1 && line !== false; n--)
		line = this.nextLine(line);
	  return line;
	},
	lineNumber: function(line) {
	  var num = 0;
	  while (line !== false) {
		num++;
		line = this.prevLine(line);
	  }
	  return num;
	},

	// Old number-based line interface
	jumpToLine: function(n) {
	  this.selectLines(this.nthLine(n), 0);
	  this.win.focus();
	},
	currentLine: function() {
	  return this.lineNumber(this.cursorPosition().line);
	}
  };

  CodeMirror.InvalidLineHandle = {toString: function(){return "CodeMirror.InvalidLineHandle";}};

  CodeMirror.replace = function(element) {
	if (typeof element == "string")
	  element = document.getElementById(element);
	return function(newElement) {
	  element.parentNode.replaceChild(newElement, element);
	};
  };

  CodeMirror.fromTextArea = function(area, options) {
	if (typeof area == "string")
	  area = document.getElementById(area);

	options = options || {};
	if (area.style.width) options.width = area.style.width;
	if (area.style.height) options.height = area.style.height;
	if (options.content == null) options.content = area.value;

	if (area.form) {
	  function updateField() {
		area.value = mirror.getCode();
	  }
	  if (typeof area.form.addEventListener == "function")
		area.form.addEventListener("submit", updateField, false);
	  else
		area.form.attachEvent("onsubmit", updateField);
	}

	function insert(frame) {
	  if (area.nextSibling)
		area.parentNode.insertBefore(frame, area.nextSibling);
	  else
		area.parentNode.appendChild(frame);
	}

	area.style.display = "none";
	var mirror = new CodeMirror(insert, options);
	return mirror;
  };

  CodeMirror.isProbablySupported = function() {
	// This is rather awful, but can be useful.
	var match;
	if (window.opera)
	  return Number(window.opera.version()) >= 9.52;
	else if (/Apple Computers, Inc/.test(navigator.vendor) && (match = navigator.userAgent.match(/Version\/(\d+(?:\.\d+)?)\./)))
	  return Number(match[1]) >= 3;
	else if (document.selection && window.ActiveXObject && (match = navigator.userAgent.match(/MSIE (\d+(?:\.\d*)?)\b/)))
	  return Number(match[1]) >= 6;
	else if (match = navigator.userAgent.match(/gecko\/(\d{8})/i))
	  return Number(match[1]) >= 20050901;
	else if (match = navigator.userAgent.match(/AppleWebKit\/(\d+)/))
	  return Number(match[1]) >= 525;
	else
	  return null;
  };

  return CodeMirror;
})();
